Please do not let conservatism confuse you. What you say above applies to the nonsense of economic conservatism, but not real economic science, which is very mathematically based, something that economic conservatism utterly rejects, in part because true mathematically based economic science such conservative silliness such as government being evil and taxation and government spending as necessarily something that slows down economic growth.

To see that what I'm saying is true, just actually look at the most successful economies in history when they were the most successful:

The most prosperous times for the US including when its prosperity was spread out most evenly were when it most closely adhered to true mathematically based economic science, during the most liberal, progressive, pro-union, big-government years in US history, the generation after WWII. (The top tax brackets for both regular income and capital gains were in the neighborhood of 70% or higher then.)

The richest countries in the world in the past couple of decades - in world history in fact - adjusted for population are the Scandinavian democracies, with their world's highest levels of taxation and social welfare, and their vastly intelligently designed capitalism, especially Norway.

China has followed most probably the economic model of Norway, the richest major country in the world adjusted for population. (I say this in part because some striking similarities in the economies of the two countries: For each, for instance, roughly 1/3 of all publicly traded companies are controlled by government via ownership of a majority of the stock of the companies. And that does not include companies their governments totally own.)

These world's most successful countries in terms of either per capita nominal GDP or growth even in the face of world wide recession follow very much what their mathematical economists say.

Read Paul Krugman's blog and see just the tip of the iceberg as to the fact that these guys do in fact know what they are talking about, and that the proof of this is when countries actually truly apply their ideas.